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余倍体小滨麦与普通小麦杂交后代的细胞遗传学研究 总被引:7,自引:1,他引:6
本文对八倍体小滨麦与普通小麦杂交后代的细胞遗传学及附加染色体的传递及丢失规律进行了研究和讨论。结果表明,BC1F1与F2相比较,染色体分离范围小,并且分离向染色体数目减少偏移,有利于43、44条染色体的分离;双单体附加和单体附加后代异染色体丢失严重,分别为65.79%和61.99%,双单体附加分离出单体附加占10.53%,单体附加的传递率为26.92%,单体附加后代分离出的二体附加为5.56%,二 相似文献
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八倍体小滨麦与缺体小麦杂交的细胞遗传学研究 总被引:11,自引:3,他引:8
八倍体小滨麦与缺体小麦杂交和回交,其后代BC1F1与F2相比较,染色体分离范围小,有利于41条染色体类型的分离,若用异源双单体附加作父本与缺体回交,41条染色体类型的分离率还会提高2倍左右;单体代换在自交世代的传递率为31.91%,二体代换的分离率为19.37%,异染色体的丢失率为29.34%;二体代换在自交世代的传递率为85.26%,异染色体的丢失率为9.21%;PMCMI染色体构型为20.76”+0.31’+0.03"+0.01””,相对紊乱系数为0.01,2n=21”的细胞占86.09%。选育的二体代换系,不同程度地表现出大穗、多花、优质、抗多种病害等滨麦的优良性状。 相似文献
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普通小麦×大麦杂种后代细胞遗传学研究 总被引:5,自引:0,他引:5
普通小麦×大麦杂种与普通小麦回交,产生了具有普通小麦细胞质带有部分大麦细胞核的普通小麦-大麦属间杂种后代,对其连续多年套袋自交,测交、细胞学鉴定和定向选择,从自交后代群体中筛选出一部分异附加系、异代换系和易位系街人有大麦某些特性的小析类型,并系统地对本和二体附加系自交后代染色体的分离行为作了遗传分析。结果表明:2n=43的单体附加标株自交分离出单体附加的频率为25.6%,二体附加的频率为1.2%; 相似文献
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普通小麦与东方旱麦草异附加系和异代换系的选育与原位杂交检测 总被引:10,自引:0,他引:10
旱麦草属(Eremopyrum)是用于小麦品种改良的又-潜在的植物资源。为了筛选小麦-旱麦草异附加系、异代换系,对普通小麦品种 Fukoho×东方旱麦草属间杂种的 BC2F3代材料的96粒种子进行了染色体数目的检测,共检出15粒2n=43的种子, 8粒 2n= 44的种子,进一步对以上材料进行的基因组DNA原位杂交,共鉴定出3个单体附加系,2个二体附加系,1个双单体附加,1个小麦三体单体附加,1个附加3条东方旱麦草染色体的小麦单体,在染色体数为42的个体中,检测出1个单体代换,1个双单体代换。根据BC2F3代自交品系来源的不同,初步认为由双单体附加自交比单体附加自交选择异附加系的效率高。 相似文献
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将大赖草种质转移给普通小麦的研究:VI.端体异附加系的选育与鉴定 总被引:1,自引:0,他引:1
利用根尖细胞有丝分裂中期染色体计数,花粉母细胞减数分裂中期1(PMC MI)染色体构型分析仪及C-分带,从普通小麦中国春与大赖草(LeymusracemosusLam.)杂种回交后代中,选育出两个端二体异附加系95G09,95G11和一个添加了一对大赖草第14号染色体和另一对端体的双重异附加系95G302(2n=44+2t),它们的PMC MI染色体配对构型分别为0.21个单价体(其中0.16个端 相似文献
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将大赖划种质转移给普通小麦的研究 总被引:17,自引:7,他引:10
大赖草比抗病品种“苏麦3号”更抗小麦赤霉病。经离体和活体赤霉病抗生单花滴注鉴定和有丝分裂中期及减数分裂中期I的C-分带分析,选育出添加了1对第2染色体的抗赤霉病异附加系,其44条染色体在MI配成0.12-0.401+21.70-21.93Ⅱ+0.01-0.04Ⅳ。经C-分带和生物素记的染色体组DNA作探针的分子原位杂交分析证实分析证实添加的1对我源染色全在MI配成二价体,在细胞学上已基本稳定。 相似文献
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甘蓝型油菜与蓝花子远缘杂交及双二倍体的合成研究 总被引:16,自引:5,他引:11
甘蓝型油菜品种奥罗×蓝花子杂种F-1,平均配对构型为12.1Ⅰ+6.53Ⅱ+0.41Ⅲ+0.18Ⅳ+0.18Ⅴ,A、C染色体组与R染色体间存在配对,它们之间具有一定的同源性。在甘蓝型油菜与蓝花子的杂种F-1代中,存在一种染色体不配对的减数分裂类型。这一类型中有少量可形成平衡的不减数配子。提供了油菜与蓝花子远缘杂种回交结实的细胞学根据。在MS+0.2mg/LNAA+3mg/LBA+1g/L秋水仙碱+30g/L蔗糖+8g/L琼脂的培养基中,接种甘蓝型油菜奥罗与蓝花子的杂种F-1进行加倍处理,经快速繁殖后,获得大量的染色体数为2n=56的双二倍体幼苗。上述双二倍体自交结实,在减数分裂中绝大多数细胞形成28个二价体,个别形成26个二价体和1个四价体。上述技术在油菜与蓝花子远缘杂交中首次解决了用常规方法不易获取远种杂种稳定双二倍体的难题。甘蓝型油菜品种Altex×蓝花子杂种F-1代,长时间的快速繁殖后,出现了染色体丢失和加倍,有形成19条染色体的配子回复到甘蓝型油菜染色体组成的趋势。在油菜远缘杂种中发现了类似于球茎大麦远缘杂种中染色体丢失的现象。 相似文献
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将大赖草种转移给普通小麦的研究Ⅵ.端体异附加系的选育与鉴定 总被引:1,自引:0,他引:1
利用根尖细胞有丝分裂中期染色体计数、花粉母细胞减数分裂中期I(PMCMI)染色体构型分析以及C-分带,从普通小麦中国春与大赖草(LeymusracemosusLam.)杂种回交后代中,选育出两个端二体异附加系95G09.95G11和一个添加了一时大赖草第14号染色体和另一对端体的双重异附加系95G302(2n=44+2t),它们的PMCMI染色体配对构型分别为0.21个单价体(其中0.16个端体单价体)、19.57个环状二价体+2.32个棒状二价体(其中0.92个由两端体配对构成),1.52个单价体(1.44个端体单价体)+18.07个环状二价体+3.17个棒状二价体(0.28个由两端体配对构成),1.03个单价体(0.72个端体单价体)+18.89个环状二价体+3.61个棒状二价体(0.64个由两端体配对构成)。运用单花滴注技术对这些材料在活体和离体条件下进行赤霉病人工接种鉴定,结果表明:95G302的抗性与抗赤霉病对照品种苏麦3号相仿;95G11的抗性高于苏麦3号,明显高于亲本品种中国春。还对端体附加系的利用以及有效、快捷地转移赤霉病抗性基因进行了讨论。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献